Electrical assembly



March 25, 1958 w. F. WINGARD 2,828,393 I ELECTRICAL ASSEMBLY Filed Nov. 10. 1953 30 Fiche 3e 32 \o Vd-IG FIG.3.

42 I 4o III/I117 \NVENTORt \N\LL|AM E Wm ARD- BY W/m ATTORNEY.

United States Patent ELECTRICAL ASSEMBLY William F. Wingard, Newtonville, Mass, assignor, by

mesne assignments, to United-Carr Fastener Corporatron, Boston, Mass, a corporation of Delaware Application November 10, 1953, Serial No. 391,234

2 Claims. (Cl. 200-466) This invention relates generally to electrical assemblies, and has particular reference to a switch wafer assembly.

In the construction of certain types of rotary and pushbutton switches, an insulating support plate is provided with a series of contact members mounted thereon to make selective electrical contact with a blade on a rotor or slider.

The contact members are usually formed of spring brass or bronze, and are customarily attached to the support plate by metal rivets piercing the plate. The assembly of such contacts in this manner is a relatively expensive operation, since the rivet and contact must be properly aligned by hand under a suitable press. In cases where contacts are needed on both sides of the plate the assembly operation is even more difiicult, and in cases where the contacts on opposite sides of the plate must be insulated from each other, special washers must also be included in the assembly to prevent the rivet from making an electrical circuit between the contacts it retains in assembly.

The object of this invention is to provide a switch wafer assembly in which the need for separate rivets to retain the contacts in assembly is eliminated.

A further object of the invention is to provide a switch wafer assembly in which the means retaining the contacts in assembly therein is an integral part of the support plate.

Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.

In the drawing:

Fig. 1 is a top plan view of a switch wafer assembly embodying the features of the invention.

Fig. 2 is a view in section taken on line 22 of Fig. 1.

Fig. 3 is a view in section taken on line 3-3 of Fig. 1.

Fig. 4 is a top plan view of a modified form of switch wafer embodying the features of the invention.

Fig. 5 is a view in section taken on line 55 of Fig. 4.

Fig. 6 is a view in section taken on line 66 of Fig. 4.

Fig. 7 is a view in section taken on line 7--7 of Fig. 6.

Referring to Figs. 1-3 of the drawing, there is illustrated a switch wafer assembly 10, which comprises a support plate 12 and a series of contact members 14 assembled thereon.

The wafer assembly is of the type which is provided with a central opening 16 to receive a rotor 18 having a circuit completing blades 20 and 22 mounted on opposite sides thereof. The support plate 12 is formed of a single piece of molded plastic and is provided with a series of integral protruding pins 24 and 26 on opposite sides thereof disposed about the central opening 16. Each pair of pins on opposite sides of the support plate has an aperture 28 associated therewith for a purpose to appear hereinafter.

The contact members 14 are formed of a strip of metal bent back on itself to provide a soldering terminal 30 at one end and superimposed flexible contact blade receiving jaws 32 at the other end to permit the blades on the rotor to pass therebetween. Each contact member 14 is also provided with a projecting tang 34 and an aperture 36 in the medial portion.

The contact members 14 are assembled onto the support plate by placing them thereon so that an integral pin on the plate extends through the aperture 36, and the tang 34 projects into the aperture 28 associated therewith. The pin is then headed or deformed by a suitable tool, with the application of heat, if required by the type of plastic of which the plate is made, so that the end of the pin spreads laterally over the contact member and retains it tightly against the plate, and the projecting tang 34 prevents rotation of the contact member on the plate.

It is evident that a contact member may be assembled onto both sides of the plate, as illustrated in Fig. 2, without any electrical contact resulting from such assembly.

It is also evident that although pins are provided about the entire periphery of the opening in the plate, contact members need be assembled only onto such pins as are necessary to provide the desired circuits.

Referring to Figs. 47 of the drawing, there is illustrated a modified form of switch wafer 40, comprising a support plate 42 and a series of contacts 44 assembled therein. The support plate 42 is provided with a central opening 46, and a series of slot-like radially extending elongated recesses 48 disposed thereabout, with projecting pins 50 disposed in the slots.

The contacts 44 are similar to the contacts 14 previously described, with the exception that no projecting tang is necessary. The contacts 44 have an aperture 52 and are seated in the elongated recesses 48 with a pin 50 extending through the aperture 52, said pin being headed or deformed above the contact as previously described to retain it in place on the support plate. The fact that the contact 44 is seated in the elongated recesses 48 prevents rotation of the contact on the support plate.

The illustrated switch wafers are particularly adapted for economical assembly, since only the contact member and the support plate need be handled during assembly, no separate rivets or washers being necessary.

Since certain obvious changes may be made in the device without departing from the scope of the invention, it is intended that all matter contained herein be interpreted in an illustrative and not in a limiting sense.

I claim:

l. A switch Wafer assembly, comprising a support plate and a series of contact members mounted on a surface thereof, said support plate being formed of a single piece of molded synthetic organic thermoplastic material and having a series of integral contact receiving pins projecting from said surface, each contact member having an aperture therethrough receiving a pin, the end of said pin being deformed to provide a laterally extending portion bearing against the upper surface of the associated contact member to retain the contact in assembly on the support plate free of any metal fastening members.

2. A switch wafer assembly as set forth in claim 1 in which the support plate has integral contact receiving pins on opposite sides for receiving and holding contacts on both sides of said supporting plate when desired.

References Cited in the file of this patent UNITED STATES PATENTS 2,079,003 Dick May 4, 1937 2,195,237 Bryant of a1. Mar. 26, 1940 2,594,190 Mastney Apr. 22, 1952 2,609,570 Danielson et a1. Sept. 9, 1952 

